Shortridge can't get over Portland. She only lived here for a few years, but it was where she enjoyed her first success as a novelist and made lots of wonderful friends. "It really worked for me," she said.

Portland is also the place where Shortridge found the inspiration for her new book, "When She Flew." It's set in a lightly fictionalized version of the city she calls Columbia and is based on a father and daughter who lived in Forest Park for several years before being discovered in 2004.

Like many people, Shortridge was "completely mesmerized" by the story of a man and his 12-year-old daughter, clean and well-behaved, who lived in a hidden camp and went into town for food and supplies. They were taken to live on a horse farm in Yamhill County by Michael Barkley of the Portland Police Bureau but slipped away after the man complained of media intrusions and worried that his daughter would be teased at school. Their whereabouts are unknown.

Everything about the case fascinated Shortridge, especially the idea that a police officer would go out of his way to try to do the right thing. She sent Barkley an e-mail complementing him on his actions and they eventually became friends. Barkley led her up a steep slope in Forest Park on a hot August day and showed her the camp where the father and daughter lived. It's overgrown now, but there was a tree with a blue tarp and the ground was packed down. Barkley kicked at a log and pulled out a red yo-yo, which sits on Shortridge's desk.

"It definitely felt like there were ghosts there," she said.

Shortridge is not the only writer to be inspired by the father and daughter in Forest Park. Peter Rock, a professor at Reed College, used their story as the basis for his novel "My Abandonment," published earlier this year to wide acclaim. Shortridge was worried when she heard about Rock's book and thought people would think she copied him if the novels were too close in approach and style. She read "My Abandonment" and was doubly relieved -- that it was excellent and that Rock had a different take than hers.

"I love his book," Shortridge said. "The writing is so gorgeous, but it's really different than mine. He takes it in a whole different direction."

"When She Flew" uses alternate chapters to tell the story of the father and daughter and of Jessica Villareal, the police officer who finds them. Shortridge said she was interested in writing about parents and children, cops, the treatment of veterans, the media and what makes a home. She was happy that Barkley and his wife read "When She Flew" and gave it their blessing and stressed that it was inspired by the events in Forest Park but not based on them.

"There's a lot of truth in it, but it's not about real people," she said.